Originally Posted by
Rambuster
Fuel surcharges depend on the airline code booked and not the metal used.
In the past LH had higher fuel surcharges than UA. (I believe this gap is now more or less closed).
The gap is not at all closed. I just worked on the best business fare for ACC-FRA-JFK RT. Z fare on exactly the same flights but all UA code share is a total of 2911USD while all LH flight numbers work out to 3380USD. YQ surcharge is 300USD vs. 400USD respectively. The remainder is actually due to a basic fare difference while the fare rules are completely identical.
Boy, I am glad I found this, as I usually would always go for the "native" LH flight numbers.